Hillenburg began his career in animation back in 1987, Variety reports. The SpongeBob SquarePants series premiered in July of 1999 and eventually went on to air nearly 250 episodes.

"We are sad to share the news of the passing of Stephen Hillenburg, the creator of SpongeBob SquarePants. Today, we are observing a moment of silence to honor his life and work," Nickelodeon share to Twitter.

Hillenburg had announced his diagnosis in March of 2017 and had served as a creative partner to the network. In addition, he went on to produce and direct The SpongeBob SquarePants Movie in 2004.